From eb98ab58cb48980779525bcbe25a3f0a04c77266 Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Sat, 22 Jun 2013 00:45:18 -0500
Subject: [PATCH] add 'horizontal-side-conditions-same-line style to
 rule-pict-style

---
 pkgs/redex/pict.rkt              | 11 ++++++-----
 pkgs/redex/private/pict.rkt      | 24 ++++++++++++++++--------
 pkgs/redex/scribblings/ref.scrbl | 15 +++++++++------
 3 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/pkgs/redex/pict.rkt b/pkgs/redex/pict.rkt
index 367227779b..64931ce3de 100644
--- a/pkgs/redex/pict.rkt
+++ b/pkgs/redex/pict.rkt
@@ -8,11 +8,12 @@
          texpict/mrpict)
 
 (define reduction-rule-style/c
-  (symbols 'compact-vertical
-           'vertical 
-           'vertical-overlapping-side-conditions
-           'horizontal-left-align
-           'horizontal))
+  (or/c 'vertical 
+        'compact-vertical
+        'vertical-overlapping-side-conditions
+        'horizontal
+        'horizontal-left-align
+        'horizontal-side-conditions-same-line))
 
 (provide reduction-rule-style/c render-term term->pict
          term->pict/pretty-write
diff --git a/pkgs/redex/private/pict.rkt b/pkgs/redex/private/pict.rkt
index ac9fdfad77..1068abff32 100644
--- a/pkgs/redex/private/pict.rkt
+++ b/pkgs/redex/private/pict.rkt
@@ -179,7 +179,7 @@
 (define current-label-extra-space (make-parameter 0))
 (define reduction-relation-rule-separation (make-parameter 4))
 
-(define ((rule-picts->pict/horizontal left-column-align) rps)
+(define ((rule-picts->pict/horizontal left-column-align side-conditions-same-line?) rps)
   (let* ([sep 2]
          [max-rhs (apply max
                          0
@@ -208,11 +208,17 @@
                       [label (hbl-append (blank (label-space) 0) (rp->pict-label rp))]
                       [sep (blank 4)])
                   (append 
-                   (list lhs arrow rhs label
-                         (blank) (blank)
-                         (let ([sc (rp->side-condition-pict rp max-w)])
-                           (inset sc (min 0 (- max-rhs (pict-width sc))) 0 0 0))
-                         (blank))
+                   (if side-conditions-same-line?
+                       (list lhs arrow 
+                             (hbl-append rhs
+                                         (let ([sc (rp->side-condition-pict rp max-w)])
+                                           (inset sc (min 0 (- max-rhs (pict-width sc))) 0 0 0)))
+                             label)
+                       (list lhs arrow rhs label
+                             (blank) (blank)
+                             (let ([sc (rp->side-condition-pict rp max-w)])
+                               (inset sc (min 0 (- max-rhs (pict-width sc))) 0 0 0))
+                             (blank)))
                    (if (= len i)
                        '()
                        (list sep (blank) (blank) (blank))))))))
@@ -425,9 +431,11 @@
     [(vertical-overlapping-side-conditions)
      rule-picts->pict/vertical-overlapping-side-conditions]
     [(horizontal-left-align)
-     (rule-picts->pict/horizontal ltl-superimpose)]
+     (rule-picts->pict/horizontal ltl-superimpose #f)]
+    [(horizontal-side-conditions-same-line)
+     (rule-picts->pict/horizontal rtl-superimpose #t)]
     [else ;; horizontal
-     (rule-picts->pict/horizontal rtl-superimpose)]))
+     (rule-picts->pict/horizontal rtl-superimpose #f)]))
 
 (define (mk-arrow-pict sz style)
   (let ([cache (make-hash)])
diff --git a/pkgs/redex/scribblings/ref.scrbl b/pkgs/redex/scribblings/ref.scrbl
index 6585b8861e..d35959436f 100644
--- a/pkgs/redex/scribblings/ref.scrbl
+++ b/pkgs/redex/scribblings/ref.scrbl
@@ -2803,7 +2803,9 @@ variant, the side-conditions don't contribute to the width of the
 pict, but are just overlaid on the second line of each rule.  The
 @racket['horizontal-left-align] style is like the @racket['horizontal]
 style, but the left-hand sides of the rules are aligned on the left,
-instead of on the right.
+instead of on the right. The @racket[''horizontal-side-conditions-same-line]
+is like @racket['horizontal], except that side-conditions
+are on the same lines as the rule, instead of on their own line below.
 
 }
 
@@ -2811,11 +2813,12 @@ instead of on the right.
 
 A contract equivalent to
 
-@racketblock[
-(symbols 'vertical 
-         'compact-vertical
-         'vertical-overlapping-side-conditions
-         'horizontal)
+@racketblock[(or/c 'vertical 
+                   'compact-vertical
+                   'vertical-overlapping-side-conditions
+                   'horizontal
+                   'horizontal-left-align
+                   'horizontal-side-conditions-same-line)
 ]}
 
 @defparam[arrow-space space natural-number/c]{